Engine Clatter at Startup

[AZowner]

After letting my 350 sit for 10 days, I had abnormal what sounded like valve clatter at startup. The engine ran very rough for about 15 seconds before oil pressure built up.

Has anyone experienced a similar event? I theorize it was because ALL the oil had drained to the oil pan and I had clatter until the pressure built up. Sounded like marbles in a can.

Of course, being Mr. Proud Owner, I visualize extensive engine damage with the abnormal noise. When warm, startup is normal.

Thanks for any advice

[zrated]

does the noise do it on the second start up? and is the noise heard continuously

[AZowner]

Originally Posted by zrated

does the noise do it on the second start up? and is the noise heard continuously

No, the second or subsequent start ups are fine. The noise only occurs on the first startup after the car sits overnight or for a period of time. Sure appreciate you're inquiry.

[bad68chev]

Noise is most likely caused by the timing chain. The timing chain on those cars uses a hydraulic tensioner, when they sit for a long time the tension backs off due to oil bleed off. When you start the car chain has some slack in it until oil pressure builds back up. This is normal and won't hurt anything on vehicle. Maximas and altimas will do the same thing if they sit for long periods of time without being started.

['luder]

I'm fairly new to the timing CHAIN gang, but I also know that even timing belt cars will also do this. Not the timing belt, but the actual valves. After letting your car sit for that long...like bad68chev said...there's "oil bleed off". The parts of the engine are pretty much 'dry' of oil and for a few seconds..while the oil pressure builds up..your car will chatter a bit. So..in a timing chain car..it may be both the valves AND the chain chattering.

-Andy

[wlittleman]

This is an ancient thread, but I'd like to resusitate it because I have this problem. I have intermittent zero or very low oil pressure on some startups. Sometimes, the oil pressure shoots up after 5 to 10 seconds, but at other times, it doesn't seem to 'wake up'. I usually turn off the engine after 20 seconds for the fear of damaging the engine. My car is an '04 350z, and it was worked very well until last week.

AZowner, what was your final diagnosis?